Rock drill

ABSTRACT

A rock drill having a head body, a sleeve fixed to the inside of the head body, a drilling tool attached with a bit to one end thereof and slidably and rotatably engaged with the sleeve, a main body connected to the head body, a hydraulically operated drill hammering means for imparting reciprocal movement to said tool, a drill rotating means for rotating the tool, and an air blast means for blasting air from the tool to remove the crushed rocks around the tool. Since hydraulic liquid can be utilized for operating the rock drill thus constructed, it may be easily adapted for use with bulldozers, construction vehicles, and the like.

United States Patent Motokura Feb. 18, 1975 [54] ROCK DRILL 3,666,024 /1972 Beaumont 173/105 [75] Inv o Mi Motoku a, Osaka Japan 3,701,386 /1972 Feucht 173/116 [73] Assignee: Kabushiki Kaisha Komatsu primary E i j A Leppink Selsakusho, y Japan Attorney, Agent, or Firm-Oblon, lFisher, Spivak, 22 Filed: July 13, 1973 Mcclelland & Mam

[21] Appl. No.: 379,075

[57] ABSTRACT Foreign li i p i b A rock drill having a head body, a sleeve fixed to the July 14 1972 Japan 47 69886 inside of the head body, a drilling tool attached with a Jul 1972 Ja an 47 69888 bit to one end thereof and slidably and rotatably en- 1972 47 82989 gaged with the sleeve, a main body connected to the y p head body, a hydraulically operated drill hammering [52] U S Cl 1.73/ l73/108 means for imparting reciprocal movement to said tool, [51] H} Bzsd 9/00 a drill rotating means for rotating the tool, and an air blast means for blasting air from the tool to remove [58] Field of Search 1 108 the crushed rocks around the tool. Since hydraulic liq- [56] References Cited uid can be utilized for operating the rock drill thus constructed, it may be easily adapted for use with bull- UNITED STATES PATENTS dozers, construction vehicles, and the like. 2,778,605 l/1957 Hunn 173/105 3,490,549 l/l970 Catterson 173/105 7 Claims, 6 Drawing Figures 65B36u 4788 36788485814241704 1722 6' 2|-'A 9107 ROCK DRILL BACKGROUND OF THE INVENTION 1. Field of the Invention:

This invention relates to a rock drill for crushing brittle material such as rocks and concrete, and more particularly to a rock drill that crushes by perforation.

2. Description of the Prior Art:

In a conventional rock drill, pneumatic pressure is utilized for hammering the head of the perforating rod or tool. Therefore, a separate pneumatic source is required when the rock drill is used for machinery such as, for example, a bulldozer, a power shovel, or the like. Also, the power loss of pneumatic machinery is greater than that of the hydraulic machinery, and the noise exhausted from the pneumatic machine is excessive. Additionally, dust and other particles are circulated by the exhaust gas so as to undersirably pollute the atmospheric working environment. Moreover, pneumatic pressure cannot be raised higher than hydraulic pressure so that the pneumatic machine necessarily is larger than the hydraulic machine.

Further, the conventional direct-coupled motor used for a rock drill utilizes an inert gas, such as nitrogen, as resilient means for hammering the drill. Since the gas chamber for filling this working gas is provided in the interior of a mobile piston, when the gas is filled or oil that has leaked in the gas chamber is drained, it is necessary to remove the breaker tool as the working section from the body of the rock drill and to engage the fittings attached to the pistons to predetermined positions of the body, which is a complicated and timeconsuming task. Moreover, since the control valve for exhausting the liquid is switched only by the pressure difference of the inlet and outlet of a hydraulic circuit, the resistance or back pressure of the exhaust piping is limited, and the distance from the breaker to the liquid tank is restricted. Further, since the resilient chamber, such as the gas chamber, is provided in the piston as described above, it is impossible to replace it with a compression spring due to its structure.

It is, therefore, an object of the present invention to provide a rock drill which is very simply constructed with liquid as the working fluid and is easily mounted for use with construction machinery such as a normal bulldozer, a power shovel, and the like, having a hydraulic source so as to eliminate the disadvantages of the conventional rock drill such as deterioration of the working environment, excessive power loss and noise generation.

It is another object of the present invention to provide a rock drill which includes a resilient chamber in a breaker body for convenient filling of inert gas used as resilient material and for allowing easy exhaustion of oil leaked in the resilient chamber.

It is a further object of the present invention to provide a rock drill which eliminates the complicated and dangerous work of filling or supplementing the gas by adopting a compression spring as the resilient material.

It is still another object of the present invention to provide a rock drill which utilizes mechanical power in addition to the hydraulic pressure difference for the control of the exhaust liquid control valve regardless of the back pressure to provide positive and reliable operation.

It is still another object of the present invention to provide a rock drill which combines a stable reciprocal motion of small amplitude with high speed hammering without being affected by the hydraulic pressure of the exhaust side.

It is still another object of the present invention to provide a rock drill which incorporates an improved device for supporting the drill.

SUMMARY OF THE INVENTION The foregoing and other objects are attained in accordance with one aspect of the present invention through the provision of a rock drill which has a hollow head body, a hollow sleeve fixed to the inside of the head body and formed with a spline on the inner periphery thereof at one side, a tooi attached with a bit to the end thereof and also with a flange provided at the intermediate portion thereof with a hole axially formed therethrough and slidably and rotatably engaged with the sleeve, and a hollow main body connected to the head body which comprises a shell connected to the main body having an inlet port and. exhaust port for the operating liquid. I-Iydraulically operated drill hammering means are mounted on the inside of the main body and the shell for reciprocally hammering the tool, said means having a hollow piston slidably inserted into the sleeve and the main body, a passage formed axially therethrough, a stepped raised portion formed at the intermediate thereof, a reduced-diameter projection extended therefrom at one end and splined thereat, and a trigger chamber formed in the shell in communication with the inlet port of the shell for urging said piston. An annular resilient chamber having resilient materials therein is formed inside the main body around the piston for accumulating pressure. An annular piston valve is slidably inserted into the chamber and is formed with a cylindrical extension projecting therefrom into the shell with a cutout formed at the end thereof for forming a trigger pressurizing chamber in communication with the trigger chamber and with the inlet port of the shell in such a manner that the urging force of the trigger pressurizing chamber is larger than the resilient force of the resilient chamber. A valve body pressurizing chamber is formed in the resilient chamber for urging the piston valve in communication with the trigger chamber. The main body has a stepped raised portion formed on the inner periphery at an in termediate portion thereof, and a chamber is formed by the stepped raised portion of the main body and the stepped raised portion of the piston for returning the piston in communication with the inlet port of the shell. Drill rotating means for rotating the tool and having a hollow valve body mounted to a body attached to the main body over a cylindrical shell is attached to said shell. A valve slidably inserted into the valve body is provided and an intermediate piston slidably inserted into the body and the cylindrical shell and formed with a spline inside thereof is in engagement with the spline of the projection of the piston of the drill hammering means and is also formed with a spiral spline inside the other end thereof. A hollow shaft formed with a spiral spline on the outer periphery thereof is in engagement with the spiral spline of the intermediate piston. A one way clutch is provided between the shaft and the body for unidirectionally rotating the shaft. A first inlet port for pressurized liquid is formed at the body, and a first back pressure chamber is formed in one side of the valve body for returning the valve slidably inserted into the valve body in communication with the first inlet port for the pressurized liquid. A second inlet port for the pressurized liquid is formed at the body, and a first pressure chamber is formed on the outer periphery of the intermediate piston for urging the intermediate piston in communication with the second inlet port. A second back pressure chamber is formed in the other side of the valve body for urging the valve slidably inserted into the valve body in communication with the second inlet port in such a manner that the pressurizing area of the second back pressure chamber is larger than that of the first back pressure chamber. A third inlet port is formed at the body, and a second pressure chamber is formed in the intermediate piston for returning the imtermediate piston in communication with the third inlet port. A port is also formed at the intermediate piston for draining the second back pressure chamber in communication with the second back pressure chamber and also with an exhaust port for the liquid formed at the body to remove the urging force of the second back pressure chamber. Air blast means for blasting air from the end of the tool are provided to remove the crushed rocks from the hole of the tool, said means having an air intake port provided at the end of the rock drill, a first ventilating hole formed through the shaft of the drill rotating means, and an air accumulating chamber formed outside of the shaft in communication with the first ventilating hole and also with the hole of the tool. A second valve is slidably inserted into the intermediate piston of the drill rotating means, and a check valve is provided in the intermediate piston of the drill rotating means. A cylindrical projection is integrally formed from the intermediate piston of the drill rotating means for dividing the inside of the cylindrical shell to form air chambers at both sides therein that may be slidably inserted into the cylindrical shell. A third back pressure chamber is formed in the intermediate piston at one side of the second valve in communication with one of the air chambers. Also, a pressure chamber is formed in the intermediate piston adjacent to the check valve in the intermediate piston for urging the check valve to feed the air into the tool of the drill hammering means. A forth back pressure chamber is formed in the intermediate piston at the other end of the second valve in communication wihth the other of air chambers. An accumulator is provided, comprising a seat mounted therein, resilient fluid filled therein, an accumulator piston slidably inserted into the accumulator for compressing the resilient fluid, and a fluid reservoir formed by the seat and the accumulator piston therein for compensating the reverse flow of the operating liquid when the piston valve is operated for hammering the tool.

According to another aspect of the present invention, the rock drill comprises a hydraulically operated drill hammering means which has a hollow piston slidably inserted into the main body and having a stepped raised portion formed at the end thereof. A trigger chamber is formed at the end of the piston in the main body in communication with the exhaust port for the pressurized liquid only when the piston valve is moved to the exhaust port side. An annular resilient chamber is formed inside the main body around the piston through the main body for accumulating pressure and having resilient fluid therein for holding the piston valve upward. An annular piston valve is slidably inserted in the chamber and is formed with a cylindrical extension projected therefrom into the main body with a cutout formed at the end thereof forming a trigger pressurizing chamber in communication with the trigger pressurizing chamber and with the inlet port for the pressurized liquid in such a manner that the pressurizing area of the trigger pressurizing chamber is so provided that the urging force of the trigger pressurizing chamber is larger than the resilient force of the resilient chamber. A valve body pressurizing chamber is formed at the upper portion of the resilient chamber for urging the piston valve in communication with the inlet port for the pressurized liquid. The main body has a stepped raised portion formed on its inner periphery at the intermediate portion thereof and a chamber is formed by the stepped raised portion of the main body and the stepped raised portion of the piston for returning the piston in communication with the inlet port for the pressurized liquid in a state such that the piston valve is moved to the valve body pressurizing chamber.

According to still another aspect of the present invention, there is also provided a rock drill which has means for supporting the rock drill tool comprising a bracket provided in space from the axis of the tool at the end of the main body, a holder rotatably secured in the axial direction of the tool to the end of the bracket through a pin, forked at the ends so as to engage the tool with a predetermined gap from the tool in a manner such that the gap of the ends of the holder is narrower than the outer diameter of the flange of the tool. A knock pin is engaged so as to be slidable at the base of the bracket and is urged so as to be projected at the end of the bracket by a spring at the end thereof in such a manner that the end of the knock pin is engaged with the engaging hole of the base of the holder in such a state that the fork of the holder is engaged with the tool.

BRIEF DESCRIPTION OF THE DRAWINGS Various objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when considered in connection with the accompanying drawings, in which:

FIG. 1 is a side plan view of a preferred embodiment of the rock drill of the present invention;

FIG. 2 is a longitudinal sectional view of one embodiment of the rock drill constructed according to the present invention;

FIG. 3 is a lateral sectional view taken along the line IllIII of FIG. 2;

FIG. 4 is a longitudinal sectional view of another embodiment of a drill hammering device used for the rock drill of the present invention;

FIG. 5 is a view similar to FIG. 4, but using another embodiment in the resilient chamber; and

FIG. 6 is a lateral sectional view taken along the line VI-VI of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to FIGS. 1, 2 and 3 thereof, one embodiment of the rock drill constructed according to the present invention is illustrated.

The rock drill mainly comprises a drill hammering device A for hammering a tool or rod to crush rocks actuated by a direct-coupled hydraulic motor, a drill rotating device B for rotating the drill, and an air blast device C for blasting fluid such as air from the end of the drill to remove the crushed rocks from a hole therein.

Referring particularly to FIG. 2, the drill hammering device A comprises a tool or rod 1 attached with a bit to the end thereof, a hollow head body 2 mounted to a hollow main body 3, and a shell 4 connected to the main body 3. A hammering mechanism of the drill hammering device A is mounted inside the main body 3 and the shell 4. Numeral 5 designates an annular piston valve, and 6 is a piston slidably inserted into the main body 3. The piston valve 5 is also slidably inserted in the main body 3 in such a manner as will be hereafter described in greater detail. Piston 6 has a stepped raised portion 6 having a larger diameter at one end (the left end as viewed in FIG. 2) for purposes as will be hereinafter be described in greater detail. The left end of the rod 1 is inserted into the head body 2. Numeral 7 represents a flange of the tool 1. A hollow sleeve 9 is fixed inside the head body 2 and has spline 8 formed on the inner periphery thereof at the left end thereof as shown in FIG. 2, and a hexagonal hollow sleeve 11 formed hexagonally in section on the inner periphery thereof is press-fitted into the hollow sleeve 9. Thus, the left end of the rod 1 is removably engaged through the hexagonal sleeve 11. A hole 1a is preforated axially through the rod 1, and a pipe 14 is mounted in communication with the passage 13 of the piston 6 into the hole In.

An inlet port 15 and an exhaust port 16 for the operating liquid are provided within the shell 4. A passage 17 is formed in the shell 4 in communication with the inlet port 15 for the operating liquid. A trigger chamber 18 for urging the piston 6 is also formed in the shell 4 in communication with a passage 19 formed therein connected as will be hereinafter described in greater detail.

An annular resilient chamber 20 is formed inside the main body 3 around the piston 6 slidably inserted thereinto for accumulating pressure or tension from a spring such as a mechanical leaf spring 21 as shown in FIG. 2, or from pressurized gas such as nitrogen 21 as shown in FIG. 4. Numeral 22 shows a passage in communication with the passage 17 formed in the shell 4. The stepped raised portion 6' of the portion 6 is utilized as the surface for returning the piston 6 as was heretofore described. A stepped portion or raised portion 3' is also formed in the hollow main body 3 so that a chamber for returning the piston 6 is formed by the stepped portion 6' of the piston 6 as the surfaces for returning the piston 6 and the stepped portion 3' of the main body 3, and is in communication with the passage 22 through a passage 23 formed in the piston valve 5 and a passage 24 formed in the main body 3 and opened at the stepped portion 3' of the main body 3 to feed pressurized liquid therethrough into the chamber 25. Exhaust ports 26 are formed at the piston valve 5 over the entire periphery of the piston valve 5 so as to communicate the trigger chamber 18 with the exhaust port 16 formed in the shell 4. An annular groove 22a is formed on the inner peripheral wall of the resilient chamber 20, and is in communication with the inlet FIG. 2 through the passage 19 formed in the shell 4 to form a cylindrical extension of the piston valve 5, and a cutout Sb is formed on the inside: end of the extension 5a of the piston valve 5 to connect a trigger pressurizing chamber 27 with the passage 19 of the trigger chamber 18 as will be hereinafter described in greater detail. This trigger pressurizing chamber 27 is formed so as to face the end of the extension 5a of the piston valve 5, and is always in communication with the inlet port 15 for the operating liquid in such a manner that the pressurizing area of the trigger pressurizing chamber 27 will be provided such that the urging force within trigger pressurizing chamber 27 will be larger than the resilient force produced in the resilient chamber 21. A valve body pressurizing chamber 29 is provided in the leftmost end of the resilient chamber 20 between the leftmost end of the piston valve 5 and the rightmost end of the shell 4 in communication with the groove 22a formed on the inner peripheral wall of the resilient chamber 20 through passages 30 formed through the piston valve 5 and a passage 31 formed through the main body 3.

As shown in FIG. 1, the exhaust port 16 is in communication with an exhaust port 32 containing fluid for rotating the rod 1, as will be more fully described hereinafter, through conduits 33, 34 and 35 connected to an accumulator 36 which will be hereinafter described in greater detail. Numeral 37 designates a conduit connected to the inlet port 15 at one end and to a hydraulic 0 pressure source (not shown), and. 38 designates a return conduit from the accumulator 36.

The drill hammering device A thus constructed will operate as follows:

Pressurized liquid is supplied from the inlet port 15 through the passage 17 into both the trigger pressurizing chamber 27 so as to urge the piston valve 5 in a leftward direction as viewed in FIG. 2. Simultaneously, liquid is supplied into the chamber 25 for returning the piston 6 through the passage 22,. the groove or port 22a, the passage 23, and the passage 24. Thus, the piston valve 5 is urged by the force of the trigger pressurizing chamber 27 so as to overcome the tension of spring 21 within the resilient chamber 20 to move rightwardly as viewed in the drawing. In this case, the urging force of the trigger pressurizing chamber 27 is designed to be greater than the tension of the spring 21 of the resilient chamber 20.

As a result, on the one hand, since the trigger pressurizing chamber 27 is connected through the cutout 5b with the passage 19, the pressurized liquid will be fed through the passage 19 into the trigger chamber 18 for urging the piston 6. At this time, the piston valve 5 has already moved, and accordingly the exhaust ports 26 will be closed. 0n the other hand, since the chamber 25 for returning the piston 6 urges the piston 6 in the leftward direction as aforedescribed, the urging force of the chamber 25 tends to cancel the above movement of the piston 6, but the piston 6 will be moved right- 0 wardly due to the differential in the pressure bearing port 15 for the pressurized liquid through the passage areas thereof.

The rightward movement of the piston valve 5 reduces the volume of passage 23 to the chamber 25 for returning the piston 6 and at the same time connected the valve body pressurizing chamber 29 with the groove or port 22a. Such movement also connects the passage 30 and the passage 31 with the trigger chamber 18, with the result that the liquid for urging the piston valve and the piston 6 rightwardly as viewed in the drawings flows at once into the trigger chamber 18 while moving the piston rightwardly so as to make an impact on the piston 6 to hammer the tool or rod 1. At this time, when the piston 6 moves rightwardly, the urging force of the trigger chamber 18 is abruptly reduced so that it becomes less than the tensile force of the spring 21 of the resilient chamber 20. Therefore, the piston valve 5 moves leftwardly as viewed in the drawing so that the liquid in the valve body pressurizing chamber 29 will be fed into the trigger chamber 18. Thus, when the piston valve 5 is moved leftwardly, the exhaust port 26 will again be in communication with the exhaust port 16 so as to drain the trigger chamber 18. Thus, the urging force of the chamber 25 for returning the piston 6 increases so as to again move the piston 6 leftwardly.

Thus, the repeated reciprocal operation of the piston 6 results in a type of direct-coupled fluid motor in order to operate the piston 6 repeatedly to actuate the hammer.

The drill rotating device B for rotating a tool or rod for crushing rocks comprises a hollow valve body 39 mounted to a body 43 attached to the main body 3 such as by bolting a cylindrical shell 41 therebetweein. A valve 40 is slidably inserted into the valve body 39, and a piston 42 is slidably inserted into the body 43 and cylindrical shell 41. There is formed a spline 45 inside the right end as viewed in FIG. 2 of the piston 42 enmeshed with a spline 46 formed on the left end of the reduceddiameter projection of the piston 6 of the drill hammering device A, so engaged that the piston 42 will not be affected by the hammering operation of the piston 6. A spiral spline 47 is formed inside the left end of the piston 42 and is engaged with a spiral spline 48 formed on the right end of a hollow shaft 44. There is interposed a one-way clutch 49 between the shaft 44 and the body 43 so that the shaft 44 will be rotated in one direction only by the reciprocal movement of piston 42. An inlet port 51 is provided in the body 43 for introducing pressurized liquid into a back pressure chamber 53 for returning the valve 40 slidably inserted into the valve body 39 and is formed at the right end of the valve body 39 as viewed in FIG. 2. An inlet port 52 is provided in the body 43 for introducing the liquid into a pressure chamber 54 formed on the outer periphery of the piston 42 for urging the piston 42 rightwardly. Port 52 is formed with a stepped portion 42' therearound, to be described more fully hereinafter, through a passage 55 formed in the body 43 and a passage 56 of the valve40 into a back pressure chamber 57 formed at the left end of the valve body 39 for urging the valve 40 rightwardly, as viewed in the drawing. Thus, though the valve 40 slidably inserted into the valve body 39 receives the pressure from both end surfaces thereof from the back pressure chambers 53 and 57, since the pressurizing area of the back pressure chamber 57 is designed to be larger than that of the back pressure chamber 53, the urging force of the back pressure chamber 57 becomes larger than that of the back pressure chamber 53 so as to move the valve 40 rightwardly. An inlet port 50 is also provided in the body 43 for introducing the pressurized liquid through a port 58 formed in the valve body 39 and through a passage 59 formed in the body 43 into a pressure chamber 60 formed in the piston 42 so as to move the piston 42 leftwardly due to the difference of the pressure bearing areas at both sides of the piston 42. A port 61 is formed at the piston 42 so as to connect a passage 62 formed in the body 43 with the passage 55 formed in the body 43 so as to drain the back pressure chamber 57 through the exhaust port 32 to relieve the urging force of the back pressure chamber 57.

The drill rotating device B for hammering a tool or rod 1 for crushing rocks thus constructed operates as follows:

When pressurized liquid is fed from the inlet port 51 into the back pressure chamber 53, it urges the valve 40 leftwardly. Simultaneously, when the pressurized liquid is fed from the inlet port 52 through the pressure chamber 54, the passage 55, and the passage 56 into the back pressure chamber 57, it urges the valve 40 rightwardly. As described above, since the pressurizing area of the back pressure chamber 57 is formed larger than that of the back pressure chamber 53, the valve 40 is moved rightwardly as viewed in FIG. 2. When the pressurized liquid is fed from the inlet port 50 through the port 58 and the passage 59 into the pressure chamber 60, the piston 42 is moved leftwardly as was described heretofore. When the piston 42 reaches a predetermined position as it moves leftwardly the port 61 comes into communication with the passage 62 and with the passage 55 so as to drain the back pressure chamber 57 through the exhaust port 32 and to relieve the urging force of the back pressure chamber 57.

In this state, the pressure chamber 54 is shut-off from the passage 55 by the movement of the piston 42, and the pressurized liquid from the inlet port 52 will not be fed into the left back pressure chamber 57, and accordingly, the urging force of the back pressure chamber 57 will be removed with the result that only the urging force of the back pressure chamber 53 will urge the valve 40, so that the valve 40 moves leftwardly. Then, since the passage 59 comes into communication with the passage 62 when the valve 40 reaches the leftmost end of the valve body 39, the liquid in the back pressure chamber will be drained through the passage 59, the passage 62 and the outlet port 32. On the other hand, since the liquid fed from the inlet port 52 into the pressure chamber 54 still exists, the piston 42 will be moved rightwardly. When the piston 42 reaches a predetermined position, the pressurized liquid will again be fed through the passage 55 into the back pressure chamber 57 so as to move the valve 40 rightwardly.

Since the valve 40 will thereby move reciprocally, the piston 42 also moves reciprocally, and it will gradually rotate in one direction step by step in every back and forth movement due to the spiral spline engagement of the piston 42 with the shaft 44 at the spiral splines 47 and 48 thereof and the operation of the one-way clutch 49. And, as the piston 42 rotates, the rotating operation thereof will be transmitted through the piston 6 to the tool or rod 1 engaged in spline with the piston 6 and to the drill end.

In the air blast device C for blasting air from the end of the drill to remove the crushed rocks from the hole of the drill, an air intake port 63 is formed at the left side of the rock drill as viewed in FIG. 2, and a filter 64 is provided in the air intake port 63. A ventilating hole 65 is formed through the shaft 44 mounted with the one-way clutch 49 as was heretofore described so as to connect the air intake port 63 with an air accumulating chamber formed outside of the shaft 44, and is connected through the passage 13 formed in the piston 6 of the drill hammering device A with the hole la of the tool or rod 1 thereof. A valve 68 is slidably provided within piston 42 of the drill rotating device B, and a check valve 69 is also provided in the piston 42. A compressor is formed by the piston 42 of the drill rotating device B interposed between the air accumulating chamber 75 and the passage 13 of the piston 6, the valve 68 and the check valve 69, and the compressed air produced by the compressor thus constructed is fed through the passage 13 of the piston 6 and the hole 1a of the rod 1 and in operation will be blasted from the end of the rod or drill 1, as will become more clear hereinafter.

A cylindrical projection 70 is intergrally formed from the piston 42 of the drill rotating device B to divide the inside of the cylindrical shell 41 to form two air chambers 71 and 72 at both sides thereof, and is slidably inserted into the cylindrical shell 41 to expand or contact the volume within air chambers 71 and 72 when slidably moved inside of the cylindrical shell 41 integrally with the piston 42. A ventilating hole 73 is provided in the piston 42 so as to connect the left side air chamber 71 with a port 77 formed in the valve 68 which is slidably inserted into the piston 42 of the drill rotating device B. The port 77 is in communication through a ventilating hole 78 formed in the valve 68 with a back pressure chamber 79 formed in the piston 42 at the left side of the valve 68. A ventilating hole 80 is formed around the valve 68, and a ventilating hole 81 is formed in the valve 68 and is in communicating with a pressure chamber 82 formed in the piston 42 adjacent to the check valve 69 provided in the piston 42. A ventilating hole 74 is also formed in the piston 42 and is in communication with a port 83 and a ventilating hole 76 formed in the piston 42, with the air accumulating chamber 75. Further, a ventilating hole 84 is formed in the valve 68 and is in communication with a back pressure chamber 85 formed at the right side of the valve 68. In addition, a port 86 is provided at the accumulator 36 and is connected with the conduit 35 through the conduits 34 and 33 and the exhaust port 16 of the drill hammering device A so as to receive the operating liquid from the drill hammering device A and also to receive the liquid from the drill rotating device B through the exhaust port 32. The accumulator 36 comprises a seat 36a mounted therein, a resilient material such as gas 87 filled therein, a piston 88 slidably inserted into the accumulator 36 for compressing the gas 87, and a fluid reservoir 89 formed by the seat 36a and piston 88 and in communication with the port 86.

In the operation of the air blast device C, when the valve 68 is moved leftwardly as viewed in FIG. 2, the cylindrical projection 70 also moves leftwardly so as to contract the volume within left side air chamber 71, and the compressed air forced therefrom is fed through the hole 73 to the port 77, and is then fed through the hole 78 to the back pressure chamber 79 so as to move the valve 68 rightwardly. Accordingly, the port 77 of the valve 68 will be in communication with the ventilating hole 80 so that the air from the air chamber 71 will be fed through the ventilating holes 80 and 81 to the pressure chamber 82 so as to urge the check valve 69 to feed the air into the passage 13 of the piston 42.

On the other hand, the right side air chamber 72 intakes the air through the ventilating hole 74, the port 83 and the hole 76 from the air accumulating chamber 75 formed around the shaft 44.

When the piston 42 moves rightwardly (opposite to the above), the cylindrical projection also moves rightwardly so as to contract the volume within right side air chamber 72, and the compressed air forced therefrom flows opposite to the above. That is, the air from the air chamber 72 is fed through the ventilating hole 74 into the port 83. As the valve 68 is also moved rightwardly, the port 83 will be opened so that the air from the air chamber 72 will be fed through the ventilating hole 84 to the back pressure chamber 85 formed at the rightside of the valve 68 so .as to move the valve 68 leftwardly. Accordingly, the port 83 will be in communication with the ventilating hole so that the air will be fed to the pressure chamber 82 so as to urge the check valve 69 and then fed to the passage 13 of the piston 42.

On the other hand, the left side air chamber 71 intakes the air through the ventilating hole 73, the hole 76, and the port 77 from the air accumulating chamber 75.

The accumulator 36 compensates for the reverse flow of the liquid when the piston. valve 5 is operated for hammering the tool 1.

In operation of the rock drill thus constructed, when the pressurized liquid if fed from the inlet ports 15, 50, 51 and 52, the liquid supplied from the inlet port 15 through the passage 17 into the trigger pressurizing chamber 27 urges the piston valve 5 so that the liquid will be fed through the passage 19 into the trigger chamber 18 so as to urge the piston 6 of the drill hammering device A in order to hammer the rod 1 to perforate the rock by means of the bit attached to the end of the rod 1.

Subsequently, when the liquid is fed from the inlet port 51 into the back pressure chamber 53, it urges the valve 40 leftwardly, and simultaneously as the liquid is also fed from the inlet port 52 through the pressure chamber 54, the passage 55 and the passage 56 into the back pressure chamber 57, it urges the valve 40 rightwardly. When the liquid is fed from the inlet port 50 through the port 58 and the passage 59 into the pressure chamber 60, the piston 42 is moved reciprocally as was heretofore described so that the valve 40 will also move reciprocally. The piston 6 will be rotated in one direction step by step during every back and forth movement of the spiral spline engagement of the piston 42 with the shaft 44 by the one-way clutch 49. This rotating operation of the piston 42 will be thereby transmitted through the piston 6 to the rod 1. Simultaneously, the compressed air from the air blast device C will be blasted from the end of the rod 1 as the piston 42 is reciprocally operated to blast the hammered rocks therearound.

It should be understood from the foregoing description that the rock drill of the present invention may be constructed in a compact manner, and since only liquid is utilized as the operating fluid, it may be easily provided for use with construction machinery such as a common bulldozer having a hydraulic source. The present invention also eliminates the disadvantages of conventional rock drills that use a pneumatic pressure system which pollutes the working environment, consumes an excessive amount of power, and produces excessive noise.

Referring now to FIGS. 4 and 5, which show another embodiment of the rock drill of the present invention, a cylindrical main body 3 is formed opened at one side 1 1 coaxially with the axis of the rock drill, and a bushing 109 is inserted into a hollow head body 2 for slidably holding a tool or rod 1. A piston 6 is slidably inserted into the main body 3, and has a stepped raised portion 6' having a larger diameter at the upper portion thereof "which becomes the surface for returning the piston 6. A stepped portion or raised portion 3' is also formed in the hollow main body 3 so that a chamber 25 for returning the piston 6 is formed by the stepped portion 6' as the surfaces for returning the piston 6 and the stepped portion 3' of the main body 3. A hammering surface is formed at the lowermost end surface of the piston 6 for hammering the head of the tool or rod 1 when the piston 6 is lowered as will be hereinafter described in greater detail.

An annular resilient chamber 20 is formed inside the main body 3 around the piston 6 by means of the cylindrical side wall 3a of the main body 3 for accumulating pressure or tension by means of pressurized gas such as nitrogen gas 21'. A valve 195 is provided through the main body 3 adjacent to the resilient chamber 20 for charging nitrogen gas into the chamber 20 therethrough. A sealed annular piston valve is slidably inserted in the main body 3 and is maintained upwardly by the pressure of the nitrogen gas within the resilient chamber 20. This piston valve 5 may also be held upwardly by the tension of a mechanical leaf spring having a relatively large tension as shown in FIG. 5. An annular groove 22a is formed on the inner peripheral upper wall of the resilient chamber 20, and is in communication with an inlet port for the pressurized liquid through a passage 22 formed in the main body 3. This inlet port 15 and an exhaust port 16 are connected by proper piping to a hydraulic source and tank (not shown). The annular groove 220 faces a passage 23 formed in the piston valve 5, and a passage 24 is formed in the side wall 3a of the main body 3 so as to communicate with the passage 23 at one end thereof, the other end thereof opening at the stepped portion 3 of the main body 3. A passage 30 is formed in the upper side wall 3a of the main body 3 so as to connect the resilient chamber with the chamber 25 for returning the piston 6 when the piston valve 5 and the piston 6 are lowered slightly. A valve body pressurizing chamber 29 is povided at the uppermost portion of the resilient chamber 20.

A trigger chamber 18 is formed at the upper end of the piston 6 in the main body 3 in communication with the exhaust port 16 for the pressurized liquid through the passage 19 formed in the main body 3. A cylindrical extension 5a is projected from the piston valve 5, and a cutout 5b is formed at the inside end of the extension 5a in communication with a trigger pressurizing chamber 27 and with the inlet port 15 for the pressurized liquid in such a manner that the pressurizing area of the trigger pressurizing chamber 27 is provided such that the urging force within the trigger pressurizing chamber 27 will be larger than the resilient force produced in the resilient chamber 21. Exhaust ports 26 are formed in the cylindrical extension 5a for exhausting the liquid, and inlet ports 31 are also formed in the cylindrical extension 5a for intaking the liquid for communicating the passage with the valve body pressurizing chamber 29. The exhaust ports 26 are communicated with the passage 19 when the piston valve 5 is moved upwardly.

By way of example, approximately atm. of nitrogen gas will be filled in the resilient chamber 20, and the piston valve 5 will be moved upwardly by the pressure within the resilient chamber 20.

in the operation of the rock drill constructed according to FIG. 4, pressurized liquid is fed from the inlet port 15 through the passage 22 into the trigger pressurizing chamber 27 on one hand so as to urge the piston valve 5 against the pressure of the gas 21' filled in the resilient chamber 20, and on the other hand into the chamber 25 for returning the piston 6 through the annular groove 22a, the passages 23 and the passage 24.

As a result, the trigger pressurizing chamber 27 is placed in communication through the cutout 5b with the passage 19 so that the pressurized liquid will be fed through the passage 19 into the trigger chamber 18 for urging the piston 6. At this time, the exhaust ports 26 are closed. Then, since the chamber 25 for returning the piston 6 urges the piston 6 downwardly, the urging force of the chamber 25 tends to cancel the above described movement of the piston 6, but the piston will not be moved upwardly, but rather downwardly by the urging force of the trigger chamber 18 due to the difference of the pressure bearing areas thereof.

The downward movement of the piston valve 5 reduces the volume of passage 23 to the chamber 25 for returning the piston 6, and at the same tim connects the valve body pressurizing chamber 29 with the groove 22a, and then connects through the passage 30 and the passage 31 with the trigger chamber 18 by the downward movement of the piston 6, with the result that the liquid for urging the piston valve 5 and the piston 6 downwardly flows at once into the trigger chamber 18 while moving the piston downwardly so as to force the piston 6 downwardly to impact the tool 1. At this time, when the piston 6 moves downwardly, the urging force of the trigger chamber 18 will abruptly be lowered so that it becomes lower than the pressure of the resilient gas 21' in the resilient chamber 20, and therefore, the piston valve 5 will be moved upwardly so that the liquid in the valve body pressurizing chamber 29 will be fed into the trigger chamber 18 so as to further accelerate the piston 6 downwardly.

When the pressure in the valve body pressurizing chamber 29 is further reduced, the piston valve 5 will be returned to its original position so that the exhaust port 26 will again be in communication with the ex haust port 16 so as to drain the trigger chamber 18. Thus, the urging force of the chamber 25 for returning the piston 6 will become greater so as to again move the piston 6 upwardly to its original position.

Thus, the repeated reciprocal movement of the piston 6 yields a type of direct coupled fluid motor in order to operate the piston 6 repeatedly to hammer the work.

It should be understood from the foregoing description that a hydraulically operated drill hammering means constructed according to this embodiment of the present invention utilizes gas as the resilient material contained in the resilient chamber for accumulating the pressure by the movement of the piston valve, and thus the gas may be easily supplied without removing any parts, and the liquid received by the resilient chamber may be very easily removed. It should also be understood that the resilient gas may be replaced with a compression spring as seen in FIG. 5 so as to obviate the necessity of filling a high pressure gas into the resilient chamber. It should also be understood that since the cylindrical extension a of the piston valve 5 is integrally formed with the piston valve 5, the operation of the extension 5a is entirely independent of the exhausted liquid pressure, and accordingly, stable highspeed hammering of the piston may be achieved without being affected by the liquid pressure at the exhaust side. In addition, since the passage 19 for communicating the trigger pressurizing chamber 27 with the trigger chamber 18 and the exhaust port 16 must be separated from the passage 30, the passage 19 and the passage 30 may be provided at the proper distance therebetween even if a small hammering speed is required. Therefore, the drill hammering means of this embodiment may easily be adapted to deliver a small amplitude hammering speed.

Referring again to FIG. 2 and to FIG. 6, which shows one embodiment of a device for supporting the drill of the rock drill of the present invention, a bracket 92 is provided spaced from the axis of the tool or rod 1 at the end of the main body 3, and a holder 90 is rotatably secured in the axial direction of the tool 1 to the end of the bracket 92 through a pin 91. As shown in in FIG. 6, the holder 90 is forked at the ends, and is engaged with the tool 1 with a small gap therebetween when the holder 90 is rotated around the tool 1. The gap of the ends of the holder 90 is made narrower than the outer diameter of the flange 7 of the tool 1. Numeral 93 in FIG. 1 illustrates a knock pin slidably engaged at the base of the bracket 92 designed to be urged so as to be projected from the end of the bracket 92 by a spring 94. The end of the knock pin 93 is engaged with the engaging hole 95 provided at the base of the holder 90 such that when the holder 90 is rotated so as to be engaged with the tool 1, the holder 90 will be locked in the state shown in FIG. 2 by the knock pin 93.

In the device for supporting the tool of the rock drill thus constructed, when the holder 90 is rotated to the tool 1 and is secured by the knock pin 93, the holder 90 is held as shown in FIG. 2, and the tool 1 is supported so as to prevent the disengagement of the flange 7 with the fork of the holder 90. When the knock pin 93 is drawn out from the holder 90 and the holder 90 is rotated outwardly, holder 90 disengages with the flange 7 so that the tool 1 may be freely drawn out therefrom.

It should be understood from the foregoing description that the engagement and disengagement of the holder 90 may be simply effectuated by drawing and inserting the knock pin 93 so that the mounting and removal of the tool 1 may be very simply performed.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appendedclaims the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by letters patent of the United States is:

l. A rock drill comprising:

a hollow head body;

a hollow sleeve fixed to the inside of said head body and formed with a spline on the inner periphery thereof at one side;

a tool attached with a bit to the end thereof and with a hole axially formed therethrough and slidably and rotatably engaged with said sleeve;

a hollow main body connected to said head body having an inlet port and exhaust port for operating liquid, comprising hydraulically operated drill hammering means mounted inside of said main body for reciprocally hammering said tool, having a hollow piston slidably inserted into said sleeve and said main body and having a passage formed axially therethrough and a stepped raised portion formed at the intermediate portion thereof and a reduceddiameter projection extended therefrom at one end and splined thereat, a trigger chamber formed in said main body in communication with the inlet port of said main body for urging said piston, and an annular resilient chamber formed inside said main body around said piston for accumulating pressure and having resilient material therein and an annular piston valve slidably inserted thereinto and formed with a cylindrical extension projected therefrom into the main body;

said main body having a stepped raised portion formed on the inner periphery thereof at the intermediate portion thereof, a chamber formed by the stepped raised portion of said main body and the stepped raised portion of said. piston for returning said piston in communication with the inlet port of said shell;

drill rotating means for rotating said tool and having a body attached to said main body over a cylindrical shell attached to said main body;

a valve slidably inserted into said valve body;

an intermediate piston slidably inserted into said body and said cylindrical shell and formed with a spline inside thereof in engagement with the spline of the projection of said piston of said drill ham mering means and also formed with a spiral spline inside at the other end thereof;

a hollow shaft formed with a spiral spline on the outer periphery thereof in engagement with the spiral spline of said intermediate piston;

a one-way clutch provided between said shaft and said body for unidirectionally rotating said shaft;

a first inlet port for pressurized liquid formed in said body;

a second inlet port for the pressurized liquid formed in said body;

a first pressure chamber formed. on the outer periphery of said intermediate piston for urging said intermediate piston in communication with said second inlet port;

a thirdinlet port formed in said body;

a second pressure chamber formed in said intermediate piston for returning said intermediate piston in communication with said third inlet port;

and air blast means for blasting air from the end of said tool to remove the crushed rocks form the hole of said tool, having an air intake port provided at the end of said rock drill, a second valve slidably inserted into the intermediate piston of said drill rotating means, and a check valve provided in said intermediate piston of said drill rotating means, a cylindrical projection integrally formed from the intermediate piston of said drill rotating means for dividing the inside of said cylindrical shell to form air chambers at both sides therein in slidable insertion into said cylindrical shell.

2. The rock drill according to claim 1, wherein the resilient material of said resilient chamber of said drill hammering means comprises a gas.

3. The rock drill according to claim 1, wherein the resilient material of said resilient chamber of said drill hammering means comprises leaf springs.

4. A rock drill comprising:

a hollow head body;

a hollow sleeve fixed to the inside of said head body and formed with a spline on the inner periphery thereof at one side;

a tool attached with a bit to the end thereof and also with a flange provided at the intermediate portion thereof and with a hole axially formed therethrough and slidably and rotatably engaged with said sleeve;

a hollow main body connected to said head body comprising a shell connected to said main body and having an inlet port and exhaust port for operating liquid, hydraulically operated drill hammering means mounted inside of said main body and said shell for reciprocally hammering said tool having a hollow piston slidably inserted into said sleeve and said main body and having a passage formed axially therethrough and a stepped raised portion formed at the intermediate portion thereof and a reduceddiameter projection extended therefrom at one end and splined thereat, a trigger chamber formed in said shell in communication with the inlet port of said shell for urging said piston, an annular resilient chamber formed inside said main body around said piston for accumulating pressure and having resilient material therein and an annular piston valve slidably inserted thereinto and formed with a cylindrical extension projected therefrom into the shell with a cutout formed at the end thereof forming a trigger pressurizing chamber in communication with said trigger chamber and with the inlet port of said shell in such a manner that the urging force of said trigger pressurizing chamber is greater than the resilient force of said resilient chamber, and a valve body pressurizing chamber formed in said resilient chamber for urging the piston valve in communication with the trigger chamber;

said main body having a stepped raised portion formed on the inner periphery thereof at the intermediate portion thereof, and a chamber formed by the stepped raised portion of said main body and the stepped raised portion of said piston for returning said piston in communication with the inlet port of said shell;

drill rotating means for rotating said tool and having a hollow valve body mounted to a body attached to said main body over a cylindrical shell attached to said shell, a valve slidably inserted into said valve body, an intermediate piston slidably inserted into said body and said cylindrical shell and formed with a spline inside thereof in engagement with the spline of the projection of said piston of said drill hammering means and also formed with a spiral spline inside the other end thereof, a hollow shaft formed with a spiral spline on the outer periphery thereof in engagement with the spiral spline of said intermediate piston, a one-way clutch provided between said shaft and said body for unidirectionally rotating said shaft, a first inlet port for pressurized liquid formed in said body, a first back pressure chamber formed in one side of said valve body for returning said valve slidably inserted into said valve body in communication with said first inlet port for the pressurized liquid, a second inlet port for the pressurized liquid formed in said body, a first pressure chamber formed on the outer periphery of said intermediate piston for urging said intermediate piston in communication with said second inlet port, second back pressure chamber formed in the other side of said valve body for urging said valve slidably inserted into said valve body in communication with said second inlet port in such a manner that the pressurizing area of said second back pressure chamber is larger than that of said first back pressure chamber, a third inlet port formed in said body, a second pressure chamber formed in said intermediate piston for returning said intermediate piston in communication with said third inlet port, a port formed in said intermediate piston for draining said second back pressure chamber in communication with said second back pressure chamber and also with an exhaust port for the liquid formed in said body to remove the urging force of said secohd back pressure chamber;

and air blast means for blasting air from the end of said tool to remove the crushed rocks from the hole of said tool and having an air intake port provided at one end of said rock drill, a first ventilating hole formed through said shaft of said drill rotating means, an air accumulating chamber formed outside of said shaft in communication with said first ventilating hole and also with the hole of said tool, a second valve slidably inserted into the intermediate piston of said drill rotating means, and a check valve provided in said intermediate piston of said drill rotating means, a cylindrical projection integrally formed from the intermediate piston of said drill rotating means for dividing the inside of said cylindrical shell to form air chambers at both sides therein in slidable insertion into said cylindrical shell, a third back pressure chamber formed in said intermediate piston at one side of said second valve in communication with one of said air chambers, a pressure chamber formed in said intermediate piston adjacent to said check valve in said intermediate piston for urging said check valve to feed the air into said tool of said drill hammering means, and a fourth back pressure chamber formed in said inter mediate piston in the other said second valves in communication with the other of said air chambers; and an accumulator having a seat mounted therein, resilient fluid filled therein, an accumulator piston slidably inserted into said accumulator for compressing the resilient fluid, and a fluid reservoir formed by said seat and said accumulator piston therein for compensating the reverse flow of the operating liquid when said piston valve is operated for hammering said tool.

5. A rock drill according to claim 4, wherein said hydraulically operated drill hammering means comprises a hollow piston slidably inserted into the main body and having a stepped raised portion formed at one end thereof, a trigger chamber formed at the end of said piston in said main body in communication with the exhaust port for the pressurized liquid only when said piston valve is moved to the exhaust port side, an annular resilient chamber formed inside said main body around said piston through said main body for accumulating pressure and having resilient fluid therein for holding said piston valve upward and an annular piston valve slidably inserted thereinto and formed with a cylindrical extension projected therefrom into the main body with a cutout formed at the end thereof forming a trigger pressurizing chamber in communication with said trigger pressurizing chamber and with the inlet port for the pressurized liquid in such a manner that the pres surizing area of said trigger pressurizing chamber is so provided that the urging force of the trigger pressurizing chamber is larger than the resilient force of the resilient chamber, and a valve body pressurizing chamber formed at the uppermost of said resilient chamber for urging said piston valve in communication with the inlet port for the pressurized liquid, said main body having a stepped raised portion formed on the inner periphery thereof at the intermediate thereof, a chamber formed by the stepped raised portion of said main body and the stepped raised portion of said piston for returning said piston in communication with the inlet port for the pressurized liquid when said piston valve is moved to said valve body pressurizing chamber.

6. A rock drill according to claim 4, further comprising means for supporting the tool of said rock drill having a bracket provided in space from the axis of said tool at the end of said main body, a holder rotatably secured in the axial direction of said tool to the end of said bracket through a pin and forked at the ends and so engaged with said tool with a predetermined gap from said tool in such a manner that the gap of the ends of said holder is narrower than the outer diameter of the flange of said tool, and a knock pin slidably engaged at the base of said bracket and urged so as to be projected at the end of said bracket by a spring at the end thereof in such a manner that the end of said knock pin is engaged with the engaging hole of the base of said holder when the fork of said holder is engaged with said tool.

7. A rock drill comprising: ahead body; a sleeve formed on the inside of said head body; a drilling tool slidably and rotatably engaged with said sleeve and having an air hole therein; a main body connected to said head body; hydraulically operated drill hammering means for imparting reciprocal movement to said tool having a piston slidably inserted within said sleeve and said main body and having a passage formed axially therethrough; rotating means for rotating said drilling tool having a piston slidable therein and engaged with the piston of said drill hammering means; and means for blasting air from said drilling tool to remove particulate matter from around said tool comprising an air intake port connected to said drilling tool hole through said. passage of said drill hammering means and said piston of said drill rotating means, check valve means in said piston of said drill rotating means and air accumulating means, wherein said piston of said drill rotating means operates as a compressor interposed between said air accumulating means and the passage in said piston of said drill hammering means and said check valve means for feeding compressed air through said passage of said piston of said drill hammering means to said drilling tool. 

1. A rock drill comprising: a hollow head body; a hollow sleeve fixed to the inside of said head body and formed with a spline on the inner periphery thereof at one side; a tool attached with a bit to the end thereof and with a hole axially formed therethrough and slidably and rotatably engaged with said sleeve; a hollow main body connected to said head body having an inlet port and exhaust port for operating liquid, comprising hydraulically operated drill hammering means mounted inside of said main body for reciprocally hammering said tool, having a hollow piston slidably inserted into said sleeve and said main body and having a passage formed axially therethrough and a stepped raised portion formed at the intermediate portion thereof and a reduced-diameter projection extended therefrom at one end and splined thereat, a trigger chamber formed in said main body in communication with the inlet port of said main body for urging said piston, and an annular resilient chamber formed inside said main body around said piston for accumulating pressure and having resilient material therein and an annular piston valve slidably inserted thereinto and formed with a cylindrical extension projected therefrom into the main body; said main body having a stepped raised portion formed on the inner periphery thereof at the intermediate portion thereof, a chamber formed by the stepped raised portion of said main body and the stepped raised portion of said piston for returning said piston in communication with the inlet port of said shell; drill rotating means for rotating said tool and having a body attached to said main body over a cylindrical shell attacheD to said main body; a valve slidably inserted into said valve body; an intermediate piston slidably inserted into said body and said cylindrical shell and formed with a spline inside thereof in engagement with the spline of the projection of said piston of said drill hammering means and also formed with a spiral spline inside at the other end thereof; a hollow shaft formed with a spiral spline on the outer periphery thereof in engagement with the spiral spline of said intermediate piston; a one-way clutch provided between said shaft and said body for unidirectionally rotating said shaft; a first inlet port for pressurized liquid formed in said body; a second inlet port for the pressurized liquid formed in said body; a first pressure chamber formed on the outer periphery of said intermediate piston for urging said intermediate piston in communication with said second inlet port; a third inlet port formed in said body; a second pressure chamber formed in said intermediate piston for returning said intermediate piston in communication with said third inlet port; and air blast means for blasting air from the end of said tool to remove the crushed rocks form the hole of said tool, having an air intake port provided at the end of said rock drill, a second valve slidably inserted into the intermediate piston of said drill rotating means, and a check valve provided in said intermediate piston of said drill rotating means, a cylindrical projection integrally formed from the intermediate piston of said drill rotating means for dividing the inside of said cylindrical shell to form air chambers at both sides therein in slidable insertion into said cylindrical shell.
 2. The rock drill according to claim 1, wherein the resilient material of said resilient chamber of said drill hammering means comprises a gas.
 3. The rock drill according to claim 1, wherein the resilient material of said resilient chamber of said drill hammering means comprises leaf springs.
 4. A rock drill comprising: a hollow head body; a hollow sleeve fixed to the inside of said head body and formed with a spline on the inner periphery thereof at one side; a tool attached with a bit to the end thereof and also with a flange provided at the intermediate portion thereof and with a hole axially formed therethrough and slidably and rotatably engaged with said sleeve; a hollow main body connected to said head body comprising a shell connected to said main body and having an inlet port and exhaust port for operating liquid, hydraulically operated drill hammering means mounted inside of said main body and said shell for reciprocally hammering said tool having a hollow piston slidably inserted into said sleeve and said main body and having a passage formed axially therethrough and a stepped raised portion formed at the intermediate portion thereof and a reduced-diameter projection extended therefrom at one end and splined thereat, a trigger chamber formed in said shell in communication with the inlet port of said shell for urging said piston, an annular resilient chamber formed inside said main body around said piston for accumulating pressure and having resilient material therein and an annular piston valve slidably inserted thereinto and formed with a cylindrical extension projected therefrom into the shell with a cutout formed at the end thereof forming a trigger pressurizing chamber in communication with said trigger chamber and with the inlet port of said shell in such a manner that the urging force of said trigger pressurizing chamber is greater than the resilient force of said resilient chamber, and a valve body pressurizing chamber formed in said resilient chamber for urging the piston valve in communication with the trigger chamber; said main body having a stepped raised portion formed on the inner periphery thereof at the intermediate portion thereof, and a chamber formed by the stepped raised portion of said main body and the stepped raised portion of said piston for returning said piston in communication with the inlet port of said shell; drill rotating means for rotating said tool and having a hollow valve body mounted to a body attached to said main body over a cylindrical shell attached to said shell, a valve slidably inserted into said valve body, an intermediate piston slidably inserted into said body and said cylindrical shell and formed with a spline inside thereof in engagement with the spline of the projection of said piston of said drill hammering means and also formed with a spiral spline inside the other end thereof, a hollow shaft formed with a spiral spline on the outer periphery thereof in engagement with the spiral spline of said intermediate piston, a one-way clutch provided between said shaft and said body for unidirectionally rotating said shaft, a first inlet port for pressurized liquid formed in said body, a first back pressure chamber formed in one side of said valve body for returning said valve slidably inserted into said valve body in communication with said first inlet port for the pressurized liquid, a second inlet port for the pressurized liquid formed in said body, a first pressure chamber formed on the outer periphery of said intermediate piston for urging said intermediate piston in communication with said second inlet port, second back pressure chamber formed in the other side of said valve body for urging said valve slidably inserted into said valve body in communication with said second inlet port in such a manner that the pressurizing area of said second back pressure chamber is larger than that of said first back pressure chamber, a third inlet port formed in said body, a second pressure chamber formed in said intermediate piston for returning said intermediate piston in communication with said third inlet port, a port formed in said intermediate piston for draining said second back pressure chamber in communication with said second back pressure chamber and also with an exhaust port for the liquid formed in said body to remove the urging force of said second back pressure chamber; and air blast means for blasting air from the end of said tool to remove the crushed rocks from the hole of said tool and having an air intake port provided at one end of said rock drill, a first ventilating hole formed through said shaft of said drill rotating means, an air accumulating chamber formed outside of said shaft in communication with said first ventilating hole and also with the hole of said tool, a second valve slidably inserted into the intermediate piston of said drill rotating means, and a check valve provided in said intermediate piston of said drill rotating means, a cylindrical projection integrally formed from the intermediate piston of said drill rotating means for dividing the inside of said cylindrical shell to form air chambers at both sides therein in slidable insertion into said cylindrical shell, a third back pressure chamber formed in said intermediate piston at one side of said second valve in communication with one of said air chambers, a pressure chamber formed in said intermediate piston adjacent to said check valve in said intermediate piston for urging said check valve to feed the air into said tool of said drill hammering means, and a fourth back pressure chamber formed in said intermediate piston in the other said second valves in communication with the other of said air chambers; and an accumulator having a seat mounted therein, resilient fluid filled therein, an accumulator piston slidably inserted into said accumulator for compressing the resilient fluid, and a fluid reservoir formed by said seat and said accumulator piston therein for compensating the reverse flow of the operating liquid when said piston valve is operated for hammering said tool.
 5. A rock drill according to claim 4, wherein said hydraulically operated drill hammering means comprises a hollow piston slidably inserted into the main body and having a stepped raised portion formed at one end thereof, a trigger chamber formed at the end of said piston in said main body in communication with the exhaust port for the pressurized liquid only when said piston valve is moved to the exhaust port side, an annular resilient chamber formed inside said main body around said piston through said main body for accumulating pressure and having resilient fluid therein for holding said piston valve upward and an annular piston valve slidably inserted thereinto and formed with a cylindrical extension projected therefrom into the main body with a cutout formed at the end thereof forming a trigger pressurizing chamber in communication with said trigger pressurizing chamber and with the inlet port for the pressurized liquid in such a manner that the pressurizing area of said trigger pressurizing chamber is so provided that the urging force of the trigger pressurizing chamber is larger than the resilient force of the resilient chamber, and a valve body pressurizing chamber formed at the uppermost of said resilient chamber for urging said piston valve in communication with the inlet port for the pressurized liquid, said main body having a stepped raised portion formed on the inner periphery thereof at the intermediate thereof, a chamber formed by the stepped raised portion of said main body and the stepped raised portion of said piston for returning said piston in communication with the inlet port for the pressurized liquid when said piston valve is moved to said valve body pressurizing chamber.
 6. A rock drill according to claim 4, further comprising means for supporting the tool of said rock drill having a bracket provided in space from the axis of said tool at the end of said main body, a holder rotatably secured in the axial direction of said tool to the end of said bracket through a pin and forked at the ends and so engaged with said tool with a predetermined gap from said tool in such a manner that the gap of the ends of said holder is narrower than the outer diameter of the flange of said tool, and a knock pin slidably engaged at the base of said bracket and urged so as to be projected at the end of said bracket by a spring at the end thereof in such a manner that the end of said knock pin is engaged with the engaging hole of the base of said holder when the fork of said holder is engaged with said tool.
 7. A rock drill comprising: a head body; a sleeve formed on the inside of said head body; a drilling tool slidably and rotatably engaged with said sleeve and having an air hole therein; a main body connected to said head body; hydraulically operated drill hammering means for imparting reciprocal movement to said tool having a piston slidably inserted within said sleeve and said main body and having a passage formed axially therethrough; rotating means for rotating said drilling tool having a piston slidable therein and engaged with the piston of said drill hammering means; and means for blasting air from said drilling tool to remove particulate matter from around said tool comprising an air intake port connected to said drilling tool hole through said passage of said drill hammering means and said piston of said drill rotating means, check valve means in said piston of said drill rotating means and air accumulating means, wherein said piston of said drill rotating means operates as a compressor interposed between said air accumulating means and the passage in said piston of said drill hammering means and said check valve means for feeding compressed air through said passage of said piston of said drill hammering means to said drilling tool. 